Four-Bar Linkage Mechanism for Insectlike Flapping Wings in Hover: Concept and an Outline of Its Realization

Abstract

This paper describes the concept of a four-bar linkage mechanism for flapping wing micro air vehicles and outlines its design, implementation, and testing. Micro air vehicles (MAVs) are defined as flying vehicles ca. 150 mm in size (handheld), weighing 50–100 g, and are developed to reconnoiter in confined spaces (inside buildings, tunnels, etc.). For this application, insectlike flapping wings are an attractive solution and, hence, the need to realize the functionality of insect flight by engineering means. Insects fly by oscillating (plunging) and rotating (pitching) their wings through large angles, while sweeping them forward and backward. During this motion, the wing tip approximately traces a figure eight and the wing changes the angle of attack (pitching) significantly. The aim of the work described here was to design and build an insectlike flapping mechanism on a 150 mm scale. The main purpose was not only to construct a test bed for aeromechanical research on hover in this mode of flight, but also to provide a precursor design for a future flapping-wing MAV. The mechanical realization was to be based on a four-bar linkage combined with a spatial articulation. Two instances of idealized figure eights were considered: (i) Bernoulli’s lemniscate and (ii) Watt’s sextic. The former was found theoretically attractive, but impractical, while the latter was both theoretically and practically feasible. This led to a combination of Watt’s straight-line mechanism with a drive train utilizing a Geneva wheel and a spatial articulation. The actual design, implementation, and testing of this concept are briefly described at the end of the paper.

Reducing Versatile Bat Wing Conformations to a 1-DoF Machine

“…Coupling mechanisms have frequently been used for design of MAVs that mimic insect flight. A four-bar linkage was designed for an insect-like MAV to generate the figure eight pattern of the wing tip observed in insect flight using the planar figure eight pattern of the mechanism [20]. Conn et al [5] designed a parallel crank-rocker mechanism with a single actuator that couples flapping and pitching.…”

Performance Assessment of a Calm Flapping Wind Turbine with Small Attack Angle

“…As shown in Figure 1, the wing blade is connected to the rotor by Chebyshev-dyad linkage and the wind force is converted to rotating motion via this link mechanism. Therefore, linkage mechanism plays an important role in the mechanical arena to drive the generated forces as well as to transfer the forces in different output motions [15] [16]. To confirm stability in performance, applicability with high operation speed and high load bearing capabilities, it is important to confirm the suitable combination of these linkage geometrical parameters [17] In the flapping design, the blade fixed on a predetermined point with the constant mounting angle and the wing blade moves through the unique trajectory, i.e.…”

Design of an active flapping wing mechanism and a micro aerial vehicle using a rotary actuator

“…The flapping patterns of nature's best flying and hovering creatures, such as dragonflies, hummingbirds and bees, consist of a flap or stroke and rotation or twisting of the wing, which can be divided into two types of flapping wing mechanisms: active and passive. An active mechanism is the one in which wing rotation is generated by actively rotating the wing to generate an angle of attack during each stroke [6][7][8]. Fearing et al [9] generated such active wing flapping and rotation using four-bar mechanisms driven by two non-rotary actuators.…”